Plastic vipers: influence of food intake on the size and shape of Gaboon vipers (Bitis gabonica)

Repeated measurements of captive-born Gaboon vipers Bitis gabonica from an inbred stock examined the degree to which an animal's size and shape are af fected by food intake. We also used the level of asymmetry in dorsal colora tion as an index for possible genetic (inbreeding?) effects. Both of these factors, and the interaction between them, affected phenotypes of the young snakes. Snakes raised with abundant food differed from their less well-fed siblings not only in size, but also in body mass relative to snout-vent le ngth, head length relative to snout-vent length, head width relative to hea d length, and fang length relative to jaw length. Hence, our data show that body proportions (including the feeding apparatus) can be influenced by th e environment after birth.